ENGR 230
Unger
Materials Science
Final Exam, p. 7
Name:
December 13, 2016
Fig. 8 Crystal Planes
17. Determine the Miller indices for the plane B shown in Fig. 8.
a) (2 1 0), b) (1 2 1), c) (2 0 1), d) (2 1 1), e) (0 2 \bar{1}) 17.
18. Cite the relative Burgers vector - dislocation line orientation for the screw dislocation. They
are
a) parallel, b) perpendicular
18.
19. Which of the two crystal structures have the same value for the atomic packing factor
(APF)?
a) BCC and FCC, b) BCC and HCP, c) FCC and HCP 19.
20. Determine the atom percent of zinc in a copper-zinc alloy that consists of 30 wt% Zn and 70
wt% Cu? Note: The atomic weight of copper is 63.55 amu and the atomic weight of zinc is
65.41 amu. Conversion formulas from Chapter 4 of the textbook are given by
$C_1 = \frac{C_{A_1}}{C_{A_1} + C_{A_2}} \times 100$ (4.6a), $C_1 = \frac{C_{A_2}}{C_{A_1} + C_{A_2}} \times 100$ (4.6b)
a) 14.6 at% Zn, b) 29.4 at% Zn, c) 32.8 at% Zn, d) 48.9 at% Zn, e) 63.3 at% Zn
20.
